How Much Det can an SR handle?

[JerichoNike]

Sr swap completed running excellent! boost a bit laggy but all in all job completed

THEN>

I was running intermitantly on 3 cylinders. Checked for spark-got itTiming-Just did itChecked for boost/vacuum leaksCompression was 150 across the board when installedMaf brand new and new SR harness.

????confused????WAS at LEAST

So just for the heck of it i take the fuel rail. Injector #4 is dry as a bone(scary)Its ohms to 11.6 so electrically its sound so i dropped it off today MI Midwest injections, to be tested, cleaned, and blueprinted. WILL get them BACK TOMORROW

Then i proceeded to check the plugs.Cylinder #4 white(scary) no chunks or oil

I have boosted the car maybe 5 times in 150miles(NO REALLY safer than sorry hopefully) I have been trying to learn the powerband in the Vacuum rpm's, as well as listening for other problems exhaust leaks, Brake noices

I am an ANAL BASTARD so I have not just Romped on it!

So How Much DETONATION can an SR20det handle?????

Can The motor detonate during vacuum?

Considering my cylinder # 4 was running with little to NO fuel how much damage could have been done?

Keep in mind it was an intermittent misfire/dead cylinder/Detonation symptom.

what do ya think?

BTW stock T25/ 7psi/ FMIC/ 3" exhaust/ sr maf/ hks bov/ ran like a champ 2/3rds of the time.

waiting for the clean injectors to come back 9$ per injector to do this BTW

I Now believe this to be absolutely necissary for all swaps i will do.

[godofspeed666]

Pre detonation is bad for any motor it’s like taking a hammer and beating your pistons.

And the leaner you run your engine the hotter you run your cylinder temp and exhaust temps.

also keep in mind when you run boost you need to increase fuel line pressure 1:1 ratio so it dose not run lean.

Your timing needs to be advance 6 degrease with in pre det. at you desires air/fuel ratio the computer will try and advance and retort timing as needed

[sil80]

get the problem fixed, and you will be fine.

[the converted]

Your timing needs to be advance 6 degrease with in pre det. at you desires air/fuel ratio the computer will try and advance and retort timing as needed

What? This makes no sense.

[godofspeed666]

if the timming is over advanced and or also if you are running lean it can cause pre detination.

[the converted]

I'm just wondering where this magic number 6 deg advance when it is detonating comes from, first I am hearing about it.

[godofspeed666]

when ever pre detonation occurs which is know as the rattle point the computer is going to get a signal from your knock sensor then it will retard timing in 2degree increments till it goes away. Once it goes away the ecu is going to slowly advance timing till it gets at or close to what ever the desired timing for that load is. Good rule of thumb is to have timing about 6 degrees before you get to that rattle point to provide the most effective use of the combustion processed. With out causing pre det.

Now is this always the case no depending on deferent loads and scenarios this can change just a good rule of thumb.

[the converted]

Ok, that makes sense. It originally sounded like you were saying to advance it 6 degrees when it was detonating.

[godofspeed666]

sorry for the confusion.

[liquid_cool]

the only thing i would be concerned about would be head damage at the seal area next to the headgasket and exaust side of the head...with detonation..it will eat up aluminum and burn it away in little swisscheese lookin incriment's..i have some pics on my myspace for what the dmg looks like..it can damage the sealing ability of the head to the block...depending on the severity of detonation will depend on the damage and time it takes to render the head un-usable.....my damage only took 2 weeks before i had to replace my head and re work it...hope this helps..

[JerichoNike]

Long:So i Put the cleaned injectors back in the car and still 3 cylinders!!!Lots of smelly gas.

This leads me to believe it is a coilpack so i borrowed a couple and switched it around and then she wouldnt start at all??

so then i figure what the heck ill pull the fuel pump fuse to see if i can burn out the fuel in the cyclinders. Started right up but still idled rough. thought shed run until the fuel in the lines ran out but no!!!!!!!!!!!!!1

She Ran for 2 minutes with absolutely NO FUEL PUMP FUSE????

Put the fuse back IN and again would Not start.SO im thinking FPR???? I disconnected the vacuum line to the fpr and she idles a little better without it connected

AND if i hold my finger on the vacuum line to the fpr it dies out. Like she runs better with a vacuum leak than with it connected?

Ive checked and rechecked the coils and still nothing.Ive even untaped the coilpack harness, and tested every wire for resistance all were clear.

Brand new SR wiring harness serviced by wiring specialtiesBrand new ignitor chipBrand new walbro 255lphInjectors all sent out to be cleaned?????????????????????????????????????????/

WTF this WAS an intermittent problem now its full blown!!!

Could it be the FPR flooding the motor??IACV clogged not allowing it to idle?

Keep in mind it idles with The FPR line disconnected(open Vacuum) as soon as i put my finger on it to plug the vacuum leak it dies out.

Please Help me out? This car ran like a beauty for a week!! then one day blfgggt!!!